1. Field of Invention
The present invention relates to a phosphor coating process. More particularly, the present invention relates to a phosphor coating process by photolithography.
2. Description of Related Art
A conventional phosphor coating process needs to be customized for different types of LED package. That is, different equipments may be necessary for coating phosphor film in different types of LED package. Therefore, lots of efforts are invested in phosphor coating different types of LED package, and high costs are generated.
In conventional phosphor coating practice, excess phosphor are usually applied on the LED chip during a phosphor coating in order to fully cover all LED chip, and more material costs are generated.
Although a conventional phosphor coating can fully cover all LED chip, the conventional phosphor coating cannot be uniformly formed over all LED chip due to different types of LED package, and a light-emitting efficiency is thus reduced.
Moreover, phosphor powders gather at the bottom of the conventional phosphor coating because of excess phosphors and gravity, such that the light-emitting uniformity is thus reduced.